okay this just happened to me well you start flirting a little bit more then see if he or she does it back then ask would you ever want to be more than friends ect.and if they get like strange about it just play it off and be like just kidding or some thing hahaha but im guessing they like you back to
Depends on how old you are. If you're old enough to take them out to dinner, I'd suggest asking them to dinner. It may kick off from there. If you're too young to be paying for dinner yourself, you're too young to be dating. Period.
Well, how long have you been their friend? If it's been a long time, than I guess you guys would be more attached to each other and I'd be okay to ask them out but, if It's only been for a little while, wait. If you're that daring person, than give it a try...
If they are your true friend, it may be awkward for a bit if they reject you, but if they are true friends, they will always be your friend. As for an exact answer, only you can truly decide how to ask them out. I did it a really corny way, told her to get on a game, told her I liked her, and dipped off for 5 hours, got back on, and she surprised me on that game...(Let's leave it at that ;) )